| 摘要 |
PURPOSE: Provided is a process for producing rubber phase vinyl aromatic hydrocarbon-conjugated diene copolymers having excellent transparency and a low haze value, which prevents discoloration by inhibiting the rise of pH. CONSTITUTION: The process comprises the steps of: polymerizing vinyl aromatic hydrocarbon monomers and conjugated diene monomers in the presence of a hydrocarbon solvent and an organic lithium compound as a polymerization initiator to prepare active polymers, wherein the vinyl aromatic hydrocarbon is at least one selected from the group consisting of styrene, alpha-methyl styrene, 1-vinyl naphthalene, 4-cyclo hexyl styrene, and etc. and the conjugated diene monomer is at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, isoprene, and etc.; adding water to the active polymers to finish the polymerization; adding carbon dioxide to the resultant to neutralize. The rubber phase vinyl aromatic hydrocarbon-conjugated diene copolymer contains the vinyl aromatic block having a molecular weight of 10,000-150,000g/mol and the conjugated diene block having a molecular weight of 10,000-150,000g/mol and the weight ratio of the vinyl aromatic hydrocarbon and the conjugated diene is 99:1-15:85.
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